diff --git a/codego/core/utils/utils.go b/codego/core/utils/utils.go
index b4fa4cf..7b5bb8a 100644
--- a/codego/core/utils/utils.go
+++ b/codego/core/utils/utils.go
@@ -1,23 +1,39 @@
 package utils
 
 import (
+	"encoding/json"
+	"log"
 	"sort"
 	"strings"
 )
 
 /* ---------------------------------------------------------------- *
- * EXPORTS
+ * METHODS: json
  * ---------------------------------------------------------------- */
 
-func StrListContains(list []string, x string) bool {
-	for _, obj := range list {
-		if obj == x {
-			return true
-		}
+func JsonToArrayOfStrings(s string, value *[]string) {
+	var err error
+	err = json.Unmarshal([]byte(s), &value)
+	if err != nil {
+		panic(err)
 	}
-	return false
 }
 
+/* ---------------------------------------------------------------- *
+ * METHODS: conversion
+ * ---------------------------------------------------------------- */
+
+func BoolToInt(cond bool) int {
+	if cond {
+		return 1
+	}
+	return 0
+}
+
+/* ---------------------------------------------------------------- *
+ * METHODS: for integer lists
+ * ---------------------------------------------------------------- */
+
 func Min2(x int, y int) int {
 	if x <= y {
 		return x
@@ -32,6 +48,49 @@ func Max2(x int, y int) int {
 	return y
 }
 
+func MinList(x []int) int {
+	var val int
+	if len(x) == 0 {
+		log.Fatal("Cannot compute the maximum of an empty array.")
+		return 0
+	}
+	val = x[0]
+	for i, val_ := range x {
+		if i > 0 {
+			val = Min2(val, val_)
+		}
+	}
+	return val
+}
+
+func MaxList(x []int) int {
+	var val int
+	if len(x) == 0 {
+		log.Fatal("Cannot compute the maximum of an empty array.")
+		return 0
+	}
+	val = x[0]
+	for i, val_ := range x {
+		if i > 0 {
+			val = Max2(val, val_)
+		}
+	}
+	return val
+}
+
+/* ---------------------------------------------------------------- *
+ * METHODS: for string lists
+ * ---------------------------------------------------------------- */
+
+func StrListContains(list []string, x string) bool {
+	for _, obj := range list {
+		if obj == x {
+			return true
+		}
+	}
+	return false
+}
+
 func SortStrings(list *[]string) {
 	sort.Slice(*list, func(i int, j int) bool {
 		u := strings.ToLower((*list)[i])
@@ -68,6 +127,7 @@ func UnionStrings2(list1 []string, list2 []string) []string {
 	return list
 }
 
+// assumes that listTo contains no duplicates
 func UnionStringsTo(listTo *[]string, listFrom []string) {
 	var mark = make(map[string]bool)
 	for _, item := range listFrom {
@@ -82,3 +142,11 @@ func UnionStringsTo(listTo *[]string, listFrom []string) {
 		}
 	}
 }
+
+func UnionStringsList(lists [][]string) []string {
+	var list = []string{}
+	for _, list_ := range lists {
+		UnionStringsTo(&list, list_)
+	}
+	return list
+}